Photolithography is a process of transferring the pattern of a mask to the photoresist coating the surface of the wafer. Immersion photolithography is a new advance in photolithography which the exposure procedure is performed with a liquid filling the space between the surface of the wafer and the lens. Using immersion photolithography, higher numerical apertures can be built than when using lenses in air, resulting in improved resolution. Further, while smaller device features have less depth of focus, immersion allows a slower loss of depth of focus as we progress toward printing ever smaller features. And since these benefits come without a change in exposure wavelength, existing materials and methodologies can be extended further to smaller feature sizes.